Data di pubblicazione
Data di priorità
Politecnico di Milano
Department of Chemistry Materials and Chemical Engineering
Monitoring system of construction materials degradation regards all materials with characteristic of conducting electric current by movement of their ions and, especially reinforced concrete.
Monitoring system of reinforced concrete degradation acquires different and essential electrochemical parameters such as corrosion potential of steel reinforcement, electrical conductivity and temperature of concrete from multitudes of probes installed in large reinforced concrete constructions. The corrosion potential of steel reinforcement can be measured by any reference electrode or pseudo-reference electrode; the electrical conductivity of concrete can be measured by multi rings electrodes with alternating current (AC); the temperature of concrete can be measured, for instance, by PT 100 probes.
This system consists of a first plurality of measurement channels for measuring corrosion potential of steel reinforcement, a second plurality of measurement channels for measuring electrical conductivity of concrete, a third plurality of measurement channels for measuring temperature of concrete, an electrochemical instrument and a multiplexer, which under the command of a processor, selects the measurement channels to be acquired and connects them to the instrument for electrochemical measurements.
Acquired data are stored within the processor as common digital file like “*.csv*, and they can be transferred to elaboration data center. User chooses measurement channels, time of data acquisition and eventual automatic compensation of temperature by means of user’s interface.
Campo di applicazione
Reinforced concrete structures and infrastructures around the world have reached an age in which corrosion of steel reinforcement has already been onset. In these constructions, controlling corrosion rate of steel reinforcement and predicting the constructions’ service life are required.
Corrosion of steel reinforcement in concrete brings about a progressive reduction of material’s mechanical strength giving rise to structural damages and risks for safeguarding of human life. A monitoring system of reinforced concrete degradation could aid to control material performance avoiding sudden structural failures.
A reliable service life prediction of reinforced concrete constructions could reduce high costs of their repairs.
The state of conservation of reinforced concrete can be evaluated keeping under control corrosion potential of steel reinforcement and electrical conductivity of concrete. Electrical conductivity of concrete depends on its temperature, therefore temperature of concrete should be monitored to separate this contribution from the variations of electrical conductivity due to changes of relative humidity.
Advantages of monitoring system of reinforced concrete degradation compared to prior art are shown below.
• Unless probes to install in reinforced concrete constructions, this system has very small dimensions.
• A multiplicity of measurements of corrosion potential of steel reinforcement, electrical conductivity and temperature of concrete can be carried out with a single data acquisition system.
• Using a single data acquisition system for all probes embedded in reinforced concrete construction rather than a data acquisition system for each probe generates a great economic benefit.
• This monitoring system is applicable in all types of reinforced concrete constructions, and it can be managed remotely.
• Acquired data are immediately saved to prevent loss of sensible data such as those of monitoring.
• The construction cost of the proposed monitoring system is very low especially in view of its practical utility